+ Sponsors

Thursday, 25 February 2010

What Can't Digital Do for Me?

By Ctein

In the comments to my last column, Jason asked what kind of situations I thought I might run into where digital wouldn't be able to do the job. Understand that I don't actually expect to run into any such situations; but I can never say never. My training in physics makes it very hard for me to claim anything with absolute certainty. Ask me if the sun will rise in the east tomorrow morning, and I'll feel compelled to answer, "very likely."

There are certainly situations where digital makes things difficult, possibly to the point of impracticality. Of course almost any photographic problem can be solved by throwing sufficient amounts of time, energy, and money at it, but I'm trying to be practical here. I ain't solving a digital photography problem by buying a Phase One back, any more than I'd solve a film problem by hauling around an 8x10 view camera. So, if you want to nitpick my examples, please be realistic in your nitpicking.

Medium format color negative was exquisite at rendering fine detail and texture, and I could record exposure ranges far in excess of 10 stops with excellent linearity. I'm also fond of night photography.

Digital cameras are great for doing long exposures, because they have no reciprocity failure. But they're lousy for doing long exposures, because they build up noise. You can eliminate much of the noise if you're willing to let the camera do automatic long-exposure noise reduction, which doubles exposure times. Sometimes that's impractical. If I were the kind of photographer who liked to photograph multi-hour star trails (happily, I'm not) digital would present some real difficulties, while film takes it in stride.

My photograph of the Transamerica Pyramid required more than a 30-minute exposure, because I had to stop way down to get enough depth of field (a view camera would have made life a lot easier). Absent very expensive gear, a 30-minute digital photograph would not come out anywhere as well. Fortunately, it wouldn't be necessary. Without reciprocity failure, the exposure time would drop down to about three minutes. I could likely make this photograph at ISO 400 digitally, with the exposure time under a minute. Running automatic noise reduction will then work fairly well and won't add excessive amounts of time to the endeavor.

Some situations are tougher. Digital cameras can capture very long exposure ranges, but they tend to lose good separation in the darkest detail, and heaven help you if you clip the highlights. That makes a photograph like this one of the floodlit space shuttle Columbia extremely tricky. Almost all the important detail in the scene is in the extreme highlights or shadows, and this subject uses up absolutely 100% of the range of the color negative film. If faced with such digitally, I would probably bracket like mad and merge the photographs together.

Understand this is not an easy photograph to make under any circumstances; while I could (barely) record the scene on a single frame of film, it took me weeks in the darkroom to convert that into a good print. Silver or silicon, this would end up being a lot of work.

The most difficult case is my Jewels of Kilauea book project. This subject matter is a worst-case scenario. The shiny lava gets really, really black; the iridescent highlights are really really bright. Like the shuttle photograph, what's aesthetically important about this subject matter is in the extremes; mid-tones are often irrelevant. Complicating the issue further is that this is subject matter for which texture is extremely important, and fine texture is something that digital has a lot of trouble dealing with. (There are technical reasons for that; I may devote a whole 'nother column to it, some time.)

Making satisfactory digital photographs of this subject is tough enough. Making ones that would blend in with the film photographs I've already made is not an impossible job, but it is dauntingly difficult. This one project has likely been a major factor in keeping me from coming to a decision to go 100% digital.

What changed my mind? First, I admitted that after a half dozen years of stasis, the odds of this ever becoming a book were quite small. Next was realizing that the portfolio already has well over 100 utterly dynamite photographs. That's more than enough for any exhibits or shows. If making any new digital photographs fit well with the film ones turns out to be too tough a job, I can simply decide that those photographs will never be exhibited together. Finally, in the unlikely event the book was revived, it's 90% photographed; I only need 10–20 additional photographs. What winds up on the printed page is sufficiently denatured from the originals that I'd have no problem making the book look like a seamless whole.

No photographic medium can be all things to everybody. Looking for perfection in the arts is worse than a fool's errand. I've decided that the ways in which digital is not perfect will present as little obstacle to my art as the ways in which film is not perfect. I lived with film's warts for 40 years; digital's won't faze me.

Excellent article. And by all means follow up on .... "Complicating the issue further is that this is subject matter for which texture is extremely important, and fine texture is something that digital has a lot of trouble dealing with. (There are technical reasons for that; I may devote a whole 'nother column to it, some time.)" Hopefully not confusing detail and texture, I find getting texture right in landscape photography maddening at times.

"...... Looking for perfection in the arts is worse than a fool's errand. ...... I lived with film's warts for 40 years; digital's won't faze me." - Ctein

I cannot agree with Ctein more on this. Very good point. Very good thinking.

BTW, another idea I'm totally with Ctein is what he said when talking about the Panasonic GF1: "Sure, a DSLR is better. But better is not important, good enough is." (Not exact quotation, just according to my memory.)

You touch on one assumption that interests me particularly there: the statement that the photo of the Transamerica Pyramid would've benefitted from a view-camera. On a quick inspection, it's obvious that tilt would've allowed you to run the focal-plane along the surface rather than merely stopping down.

The underlying assumption is that digital or MF doesn't do t/s lenses. Of course, they do exist for such formats, but they're unfeasibly expensive - way out of the standard "kit" packaging. It reveals a compromise: most people don't do t/s, therefore using tiny sensor-formats to achieve the DoF from nose to infinity will keep *most* people happy *most* of the time, to the extent where the lack of t/s becomes a reasonable assumption in talking about digital equipment.

Good article, but my comment is about the header. Simple, elegant, a definite improvement. Great management, Mike, to have focussed on that for the limited time it took away from everything else you do.And nice work by the man who made it.

Thank you Ctein. This is precisely the kind of thing I hoped you would write about since...well, forever. Yay! My questions are answered! (Now I have even more. I hope that it doesn't seem ungrateful. :)

You said:Digital cameras can capture very long exposure ranges, but they tend to lose good separation in the darkest detail

Can anything be done about this? I've been fighting shadow noise since I switched to digital. It is very frustrating to photograph black cats (or dark haired children) even in good light: the fur texture often the same size as the noise texture.

This is the kind of thing where I wonder if I should blame the camera, and start looking at DxOmark ratings. Maybe a different sensor would help? Clearly, that way lies madness.*

*I'm using an Olympus E-520, which I understand doesn't have a good reputation for pretty shadow noise. But hey, I could afford it. :)

Like the discussion about what is "art" (as opposed to what is "good"), and the discussion about digital vs. film (as opposed to good photo vs. crappy photo), I am not that intrigued by questions of what digital can do better or worse than film. Many answers to that question for many different questioners. Many film photographers have found digital won't suffice for the work they do, and vice versa.

What does intrigue and concern me is the cumulative effect of another photographer swearing off film, like so many before him have. This is significant to me not because of the photograper's personal evaluation of the media for his work (that's why I find it surprising TOP has spent so much bandwidth on yet another guy "goin digital," an old story that has lost its panache long ago), but because of its effect on the medium of film. We all know it is threatened and perhaps endangered, maybe even doomed, and one more guy deciding not just to try digital but to use it exclusively is one more nail in film's coffin. This is intriguing and troubling because: (1) it is unecessary to swear off any particular medium; and (2) more importantly, if film dies a part of photography dies. Film can make photos look a certain way that digital cannot, like it or not, and if film dies the art and craft of photography will be the poorer.

I wish there were more photographers, especially more middle-aged and older photographers who owe their success and their growth as artists, by and large, to film, who would have the foresight or the generosity or the insight, to realize that they can help save an entire medium -- and thus a significant facet of an art form -- by continuing to buy a few rolls of film a year.

Not just because they owe it to the medium or to those (like me) who love that medium, but also because they owe it to themselves. The quitters cannot know when they might change their mind and wish to go back, even for a while, to one of the things that kindled their love for photography. If it's gone, they too will be impoverished.

Interesting. I would just like to point out that digital's linear light response is precisely what makes it not work for me for timed, low light exposure. I took a picture of my moonlit backyard with a Canon 5D. Durn thing looks like an exposure at noon. Ditto dusk. Where did my night-time go?

Also: my next yak-trek to unelectrified parts unknown (here there be monsters), I'm taking a camera that doesn't need batteries of any kind, much less digital. Ditto rain, snow and the beach. Digital can do the beach, but I'd rather take a beater to the bathers, if you know what I mean.

Any project requiring an 8x10 B&W contact print? -- right out with digi-cams.

"photographers who owe their success and their growth as artists, by and large, to film"

I don't think any successful photographer 'owes' his success to a certain medium. It's the artistic skill, the vision, the sense for composition and for catching the right moment, for engaging the subjects etc. etc. that makes a photographer successful; the choice of medium plays second fiddle to that.

What does an artist owe to a medium? What a strange idea. Artists have abandoned one medium and taken up another forever. Painters abandoning painting and becoming sculptors, etc. HCB abandoned photography and devoted himself to painting.

Artists continuing to use film will not save it. The people who could have saved it, consumers with P&S film cameras by the millions, abandoned it years ago.

Tilt/shift is relatively independent of digital vs. film. You can buy t/s lenses from Nikon and Canon for their [D]SLRs, and you can buy digital backs for 4x5 view cameras, and I'm pretty sure there are medium-format options in the middle, too (at least with third-party tilt devices).

True, none of those are cheap options. A lens with enough coverage to allow useful tilt is more expensive than a lens without (other factors held equal), and the case holding the lens system is much more complicated (for versions to mount on rigid cameras), and they're sold in much smaller numbers, and the people buying them are only interested in top-quality optics so nobody does cheap versions.

Film is IMHO inevitably doomed. But it's going to be around for a long time yet. It's going to be a slow ramping down, not a sudden collapse (the sudden collapse part of the process is essentially over).

With vague apologies to those who are in fear of their film going away, this 55-year-old photographer has had his work reinvigorated by the onset of digital, and I've been able to do things with big prints and landscapes from DSLR shots that I could never consider in 35mm film. I also get much better low-light results (my D700 was chosen for that over all else). From where I sit, digital is significantly, in fact very strongly, superior to film in all ways that I've interacted with. (I do not claim digital is superior in all useful ways to interact with it; and people have different requirements and priorities anyway.)

Oh, and on the subject of "deciding" to leave film -- you don't have to make a formal decision IF you already have the digital equipment, and don't mind the film equipment sitting around possibly unused. Not everybody meets both criteria there.

I was dual-mode from 2000 to maybe 2005, but film use dived instantly. I think I sold my last 35mm "user" body a couple of years ago now. In my case, I unloaded film bodies because I wanted what money was available out of them, and because I wanted them to go somewhere they'd be used and appreciated. None of them were really suitable as collector pieces; too new and too well-used. (I've still got a 4x5, film only. I think I last shot with it in 2001, but it was a long time before that the previous time, too; I've just never done much 4x5.)

"Can anything be done about this?"
Carl - Are you shooting RAW and exposing to the right? That's the best way I can think of to minimize shadow noise. It's not always practical of course, depending on the dynamic range of the scene. (I also shoot an E-520.)

The reason Ctein is "the other guy who want to say he is going digital" is due to the fact that he is really well known in the film community.
Try to find reviews on enlarging lenses, prints (on APUG p.ex)...
He makes great quality experiments.
People always want arguments to support their position.

Everybody can say now "you see EVEN Ctein is goin digital".

When people have this kind of power they want to keep it.
I think it's like a political discourse when they say "you know I was there too!!Don't forget My point of view!". An ego crisis...

I don't want to annoy Ctein because I respect him seriously for his work and what I can observe of his life curse (I'm a young physicist who like strange/interesting peers!-).
But sometimes the best way for a great guy is to stay neutral, because his voice his too strong. No matter who can make use of it and put it out of context...
The reason for which I allow myself to say that:
I have the chance not to have power at all!!-)

My guess is he only "tried" to leave open doors with the latter post. He wants to stop Film but he also wants to remain strong for the readers.

The evil is made.

For those who know and like their results with film.
For those who like going" à contre-courant".
For those who don't want everything immediately and want to keep this freedom. We hope it is only a little stone in the water.

I've not used a GF1, so I imagine that's more likely Mike's quote. But I frequently express very similar sentiments.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Tim,

In fact there is a very nice tilt/shift lens for the Pentax 67, but I could never afford (and always wanted) it. Well, now I could, but I couldn't 30 years ago when I made that photograph.

A tilt/shift lens wouldn't entirely correct that extreme a situation, but it would've gotten me at least one stop more aperture, maybe two. Given the nature of long exposure reciprocity failure, that would have cut my exposure time down to somewhere between four and 10 minutes. Big improvement!

I have other nighttime photographs in my portfolio where that trick won't work-- ones where I simply needed huge depth of field and the subject matter didn't neatly arranged itself in a receding plane.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Randolph,

I neither endorse nor denigrate HDR, and I have not in the past. I object to people who think that any technique is an artistic be-all and end-all, and by and large I personally detest photographs that have obvious and visible tonal distortions to them. But whatever floats people's boats.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Carl,

I don't really know what the answer is to this problem, not having investigated very much. One way of dealing with it would be to get a camera with the longest exposure range money can buy, and make those exposures as far off the toe of the curve as you can without clipping highlights. Which, come to think of it, is much the same technique one would use with film (except film's highlight clipping isn't quite so, ummm, "binary").

Merging a range of exposures *might* work for non-moving subjects, but I'm not sure. Certainly impractical for animate ones.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dear Robert,

Well, you *can*, but it depends on how much trouble and/or money you want to invest. Chris Woodhouse has an article in the latest PHOTO Technique magazine about dealing with just this problem. But he's kind of an uber-geek when it comes to darkroom stuff, and he's willing to go through considerable trouble.

I have a local custom lab I work with that can write out beautiful 4x5 black-and-white negatives from digital files. No work and effort on my part, but it's $100 a pop.

Mentioning this not because I think you, specifically, will be interested but to make sure that people realize there are always options for printing either digital or analog photographs in either the darkroom or on the computer.

Oh, finally a problem I CAN solve! This is pretty easy once you understand what's different between the analog and digital photograph.

The first thing that's going on is that your long exposure film photographs are 30-40% more contrasty than normally exposed ones. That's because reciprocity failure is really a progressive function of diminishing light intensity, not increasing time. The film may respond to the part of the scene that would place at Zone IX with its normal ISO of, say, 100, but it's going to behave as if it were something like ISO 10 down at Zone II.

The other thing that's going on is probably your technique. You're used to underexposing nighttime scenes because you expect them to be dark, and it's very easy for film with its reciprocity failure to let you do that. Try making a daytime scene with -3 or -4 stops exposure compensation, and it will look an awful lot like a moonlit scene.

While you could replicate the effect of film simply by underexposing in the camera and then kicking the contrast way up in Photoshop, I think you'll like the following approach better. Make your photograph normally (taking care not to blow out any highlights you care about, of course). Then in Photoshop go into Curves, grab the midpoint on the curve, and drag it down to something like 60-70. You'll be amazed how much it will look like a film photograph.

If you want to make it look EXACTLY like a film photograph, you'll have to spend some time fiddling and figure out just what the right curves are for you and you may even need to use multiple curves layers set to luminosity and color blends. But this'll get you started. Once you have a set of curves adjustment layers that produce the look you like, you can just drag and drop them onto any other digital night photographs you make, and the results will be a good first guess on where you want to be.

Personally, I never want night photographs that look like the way film thinks they should look; I'm always fighting with that in the darkroom. Usually successfully, but I'm willing to throw complicated masks and dye transfer printing at the problem. That's one way that digital printing of my film negatives has made my life LOTS easier.

Hmmm. Will the sun rise in the east tomorrow? I'd suspect it to be highly unlikely.

However, I expect the horizon to lower on schedule...

(Does the sun rise? I don't know enough about astrophysics to answer - it depends on the sun's movement - but I suspect that no, it doesn't. The rotation of the earth makes sunrise seem to happen. Actually we're looking at the "horizonlowering").

Don't mean to sound negative but after reading that you made me feel like you've "Settled" for digital rather than decided on it.

Why decide on any one medium at 100% anyway?

Film or digital, large format or small, it's all just a means to an end. an artist will use whatever is available to create his art, it's the end result that's important not the road that gets you there.

Option is important and it is hope that we can have that film option. But that is group-think. It was said that all monks dine at the same table to study buddha but each is doing it their way and has to.

I guess once one explore and done with something, an individual should go on and perhaps focus on what he wants And likes to do in their next stage of their life, journey, ... If it goes deeper instead of wider this part of the journey, so be it.

Follow the example (in a way) I think I better concentrate as well. Perhaps less use my m8 and d300 but more on my hassey and 8x10. New wish for a new year. A resolution.

"Complicating the issue further is that this is subject matter for which texture is extremely important, and fine texture is something that digital has a lot of trouble dealing with. (There are technical reasons for that; I may devote a whole 'nother column to it, some time.)"

The finest painters in history have struggled with the rendering of detail, especially in landscapes (trees), because trees are essentially a MASS of DETAIL, and it's almost impossible to present a defining mass while preserving detail, at least in painting in which the scale is smaller than 1:1 or 1:2

Photography, I would suggest, has the same problem, and the answer may be to forego the detail and preserve the mass effect -- the detail being indicted rather than scrupulously carved into the negative (or file.) In this photo:

Paul Caponigro beautifully retains hints of detail in the leaves, while emphasizing the dark mass of the trees. He indicates the liveliness and fluidity of the deer, with little detail at all. And I think it's a terrific solution.

In situations were capturing the details seems critical and at the same time extremely difficult, I think it's often possible to make an aesthetic choice and go completely the opposite way, saving the mass and pulling up just enough detail to indicate to the eye what is going on - and allowing the eye complete the detail. If you insist on detail, without considering other aesthetic options, then you are limiting yourself.

(This obviously wouldn't apply to photos of a purely documentary or engineering nature.)

Thanks to Ctein for highlighting specific photographic situations that might call for film. But more basically, digital images and film images seem to me to be apples and oranges--different from the ground up. Digital cameras fall short in making images with the character of film images -- and the opposite is true, of course. This is the reason I choose one camera type over another to carry on a particular day, not the specific photographic situations I might confront. With all respect for Ctein, I'm not sure why anyone would cut himself off from a medium of expression he has so obviously mastered. Choice is good, no?

No I was talking about merging photos to extend the exposure range. I've never even tried focus stacking. Meaning to, some day.

~~~~~~~~~~~~

Dear Nicolas,

I don't care a fig about other people's petty little religious wars. The film and digital partisans can go have it out with each other, and if they want to cite me, or not, it's entirely not my problem.

I have not told, nor even suggested, what other people should do. If anyone tries to read that into my posts, that is entirely their mistake and they'll be the only ones to suffer for it. I certainly won't.

~~~~~~~~~~~~

Dear Jim,

Back in my classical mechanics class at Caltech, the prof did tell us that we *could* make the earth the fixed frame of reference and the math would work... but it would be a really, really ugly mess.

Like all artists, I have a positively ginormous ego and simply KNOW that the universe revolves around me. [g]

~~~~~~~~~~~~

Dear Bill,

No, choice is not "good." Choice merely is.

I have chosen. I have chosen to concentrate my attention and time on a particular path. I have done that many times in the past. For example, choosing to concentrate on realistic photography, choosing to concentrate on 'found' rather than 'constructed' compositions, choosing to concentrate on color prints rather than B&W prints or chromes. Just to name a few. Some choices were merely a setting aside. Others were firmly closing a door. Options can be an opportunity; they can also be a distraction.

Any artist who claims they have never done anything like that is either supernaturally versatile or supremely lacking in introspection.

There is something about film that can never be replaced. I grew up in the transition... Darkroom in the beginning, and digital now. I wish manufactures would focus on dynamic range rather than about megapixels (minus the shortcomings of sensor/film size). I think they need to reconfigure their algorithms.

I liked your answer:
" have not told, nor even suggested, what other people should do. If anyone tries to read that into my posts, that is entirely their mistake and they'll be the only ones to suffer for it. I certainly won't."
Want to act like a free electron...

It enlighten nicely the great problem about:
"Between what I thought, what I said and what you want to understand well...their are so many chances that we don't understand ourself."

As an artist you know that people perceptions are all their own. As a scientist you know already that a voice which makes authority is followed closely.
By putting that together, you have a path to understand "Why" people can follow or be convinced by somebody easily even if they are different. Probably they only adopts his speech (we are not very far away from the monkeys)

It seems that even the free electron has an incidence on what surround him...

Many years ago on a flight from London to Los Angeles, she sun set soon after take off. Then as we passed over Greenland the sun rose again (in the west) only to set for a second time as we headed south across Canada.

All to do with the lines of longitude being closer together in the far north enabling a fast moving plane to "catch up" the sun. So you were right to say "very likely" that the sun will rise in the east. It depends on where you are and the spead and direction you are traveling.

I guess this topic has exhausted itself, but I do want to say I think there's a big difference, at this juncture, between a high-profile photography writer quitting film publicly and a painter deciding to go to acrylics exclusively and fuhgedabout oils. Film, unlike oil paint, is a medium that is endangered and those of us who enjoy using it are worried about being deprived of its special qualities and being tied to the computer stake for life.

Of course artists abandon mediums all the time, but the threat to film makes this situation a bit different. (And really, how many opinion-making craft writers, like Ctein, have announced it on a mass media platform as if there's no going back?)

Now maybe "owing the medium something" is not the best word choice, but, hey, you guys know what I mean, right? Surely a vision in your mind is not art until it is translated into some medium and surely the characteristics of the medium determine, to one degree or another, the character of the final product. If you had learned your craft with digital camera and photoshop, your first 5000 images would have expressed your vision differently, viewers might interpret your work differently, and you might have taken a slightly different course as a photographer. How you work as an artist does affect what you make. Unless, of course, you're a god, bringing your perfect work into being with a breath or a word (or the push of a button).

Well anyway. Why assume a large role in killing film when it's so good? Nicholas M. gets it and said it much more poetically than I.

Bill: Realizable choice at the societal level is clearly (to me) good. On the other hand, for an individual working on a project, focus is clearly good, too.

I'm glad I live in a society where individuals can skydive, scuba dive, get a pilot's license, and paint with oils. But I've never done any of those things, and never considered any but one of those things, for myself. I don't keep a pickaxe in the trunk of my car just in case I need to make a hole in tough ground, either; that's a choice I'm deliberately closing off for myself.

For an artist, making decisions on major work directions, in the end you have to focus more narrowly than the entire array of artistic tools available at the societal level; nobody has the time to master them all or the versatility to learn them all well, or possibly even the innate ability to be successful with every single one of them.

Ctein has been Ctein long enough to have a pretty good idea what having enough information to make the right decision for him feels like. But it's also true that, if somehow he's wrong about this one -- it'll just cost him some money to buy film cameras again. His individual decision will have infinitesimal impact on the availability of film and cameras for the rest of his life. The consequence of his getting this one wrong is modest inconvenience, not death. Not that I think there's any real chance he WILL change his mind.

Hey Randolph (I assume your last post was to me) and Ctein - My bad...I for some reason thought the "bracket like mad" comment was in reference to the Trans-America pyramid photo. I.e. I thought the focus stacking would be needed to make up for the lack of tilt/shift or small enough aperture. (I also wasn't trying to be super-critical of the HDR term - I use it loosely myself. I just actually thought he was talking about a different technique!)

I've shot predominantly at night for the last 6 years with various dSLRs and a Mamiya 7 side by side. High ISO testing helps me get the exposure right with digital, and my productivity is higher because moonlit exposures are typically 5-10 minutes (instead of 20-30 minutes with film).

The long star trail issue can be handled with digital by taking multiple short exposures and stacking in post. Pretty quick and easy.

Ctein's comments about post-processing digital to look like night are spot on. Moonlight is just reflected sunlight -- if you wait long enough, night photos look like day.

An interesting addition to this topic is that slide film "reads" as night right on the light table. Shooting some slide film at night will really help you figure out how your digital night photos should look. Here's an article with examples of the same shot done with film and digital, with photos by night photography wizard Troy Paiva.

Mike, a "modeling amp," at least in theory (and I'm not a gear expert), attempts to recreate digitally the sound of different classic amps as, for example, the Vox AC30 which is associated with the British Invasion sound of groups like The Stones, Beatles, and The Kinks. It's analogous to digitally recreating the look of various classic films using software instead of film.

Surely someone must be working-on a "Dye-Transfer Plug-in" for Photoshop [grinning, ducking, and running].

I'm not a musician, but I've never heard the term "modeling amp" before.

Dear Mike, a modeling amp is basically the same as a DSLR: A highly specialized computer with some bits and pieces attached.

In this case the bits and pieces are
- an A/D-converter (think of the recording input of your computer soundcard), which captures the audio signal from the instrument,
- a software that simulates how different tube amplifiers and loudspeakers would influence the sound (a bit like the famous 'art filters' in some cameras -- do you want a Marshall stack tonight, or rather a VOX box?), and finally
- another A/D-converter, which changes the results of that simulation back into a classical audio signal.

Oh, and I almost forgot about the amp (usually transistor) and loudspeaker.

In fact, in many small project studios guitars and other instruments are no longer played through an amp, which would then be recorded by a microphone. Instead, the guitar cable goes directly into a neutral pre-amp, and then into the computer. The whole studio work -- mixing, effects (the amp simulation being only one of them), cutting, mastering, etc. -- is done in specialized software (Logic, Cubase, ProTools, etc.).

I'm a low-budget amateur who shoots 35mm film, and my biggest concern with digital is long term archiving. In 25 years, I can take out my negatives and slides from storage and they will still be there. Will my digital files on DVD still be recoverable after 25 years? I don't like the idea of having to transfer my entire life's worth of photos to a new storage medium every decade. I would be crushed if digital photos of my daughter when she was 5 years old were lost forever due to a corrupted computer file, or something else out of my control!
Sure, I understand a fire could happen, storage conditions can deteriorate negatives and slides, etc., but I think the chances of that happening are less than a digital incompatibility rendering them useless in the future. Ever try to get something off a 5-inch floppy disk these days?

About 25 years ago I made a flight from London to San Francisco the trans-Atlantic portion of which was on the Concorde*. The timing of the flights was such that I did not get to experience two sunrises... but I did get two lunches.

*(Which prompted me to rephrase Clarke's Law as, "Any sufficiently advanced technology is indistinguishable from the ordinary." It was very cramped, very noisy, and you could hardly see out the triple-pane paperback-book-sized windows.)

(On the other hand, the service was incredible, the food was astonishingly good by any restaurant standards, and Laurence Olivier was sitting two rows in front of me.)

(As we drift off-topic at supersonic speeds...)

~~~~~~~~~~~~~~~~

Dear David,

Oh, sorry; it never even occurred to me that focus stacking would be a way of handling nighttime photographs that need huge depth of field. I imagine you're right! I suppose I really should take a look at that technique... in my copious spare time...

~~~~~~~~~~~~~~~~

Dear Player,

Oh, you think you joke, but I spent some time trying to figure out how to simulate the look of dye transfer prints in Photoshop just so I could get some sense of how negatives would print before I made dye transfers from them. I could get some hints, but I never really nailed it down to my satisfaction. (Ektacolor prints were a lousy proofing medium for that purpose.)